1. Field of the Invention
The invention relates to the field of wire tensioning and feeding devices, particularly those used on semiconductor bonders, Class 226, Subclass 97.
2. Prior Art
In the packaging of integrated circuit substrates or "chips", it is necessary to connect pads on the chips to lead frames or the like. Generally, very thin (e.g. 1 mil) gold wires are bonded to the pads and the lead frames. It is difficult to manually handle these wires and to thread them through the bonding tools.
Capillary wire feed devices are known in the art which pneumatically thread wires through capillary tools. An example of one such pneumatic threading device is described in U.S. Pat. No. 3,319,859.
Other pneumatic devices have been employed to feed and direct these thin wires. An example of a frictionless pneumatic spool mount for supporting and retaining a spool of filament wire is described in U.S. Pat. No. 3,363,818.
As will be seen, the device of the present invention provides both self-threading and tensioning. Often in the prior art the tensioning is attained with mechanical arms.